Double-acting pump for gas or liquid



Dec. 1969' c. H. WICKENBERG ET AL 3,485,180

DOUBLE-ACTING PUMP FOR GAS 0R LIQUID Filed May 28, 1968 Fig.2.

INVENTOR H. WICKENBERG 1 .ZIJII/ I CHESTER SIGFRID M. OLOFSSON ATTORNEY.

3,485,180 DOUBLE-ACTING PUMP FOR GAS R LIQUID Chester H. Wiclrenberg,890 Ford Ave., Elgin, Ill.

60120, and Sigfrid M. Olofsson, Box 5880, Munkedal, Sweden Filed May 28,1968, Ser. No. 733,228 Int. Cl. F04b 19/02, 21/04 US. Cl. 103158 2Claims ABSTRACT OF THE DISCLOSURE SUMMARY OF THE INVENTION Known typesof double-acting pumps usually include a piston which is reciprocal to acylinder sealed at both ends and through which one end wall projects apiston rod. The cylinder is divided by the piston into two chamberswhich serve alternately as pumping chambers. In order to facilitate theoperation of this arrangement a valve is provided which alternatelyopens the connection between the chamber which is serving as the pumpingchamber as well as the pump outlet. This valve arrangement iscomplicated and highly expensive and difiicult to manufacture andmaintain.

The object of the present invention is to provide a double acting pistonpump which is simple and inexpensive to manufacture, reliable infunction and which can be used for pumping either liquids or gas.

This object is achieved by means of the present invention which ismainly characterized by the arrangement and construction of a pistonwhich resides within a cylinder with the piston having a relatively wideclearance between its periphery and the inner wall of the cylinder. Thepiston includes a self-contained valve means comprising a sealing ringthat is selectively positioned into sealing contact with the inner wallof the cylinder and moves relatively within an annular peripheral grooveprovided by the piston to open communication with either one of thepumping chambers defined thereby.

GENERAL DESCRIPTION The invention will best be understood by referenceto the accompanying drawings in which there is shown the preferred formof construction.

FIG. 1 shows a side elevational detailed view of the double acting pumpof this invention;

FIG. 2 is a fragmentary detailed sectional view of a modified pistonvalve as can be associated within the present invention; and

FIG. 3 is a fragmentary detailed section view of a modified valvesealing means.

FIG. 1 illustrates a double-acting pump which consists of a cylinder 1which is capable of reciprocating movement over a stationary piston 2.One end 3 of the cylinder 1 is provided with a handle 4 whichfacilitates the moving of the cylinder 1 over the stationary piston 2.The opposite end wall 5 of the cylinder is provided with a centeropening 5' through which a hollow piston rod 6 projects. The piston rod6 is mounted between and has its opposite ends closed by the piston 2and a support plate 7, the latter providing an outlet 7', which has opencommunication nited States Patent 0 with a hose 8 through which theworking medium of the pump is exhausted.

The cylinder 1 is divided by the piston 2 into two pumping chambers 9and 10 which can be alternately placed in communication with the pistonrod 6. To accomplish the above function the diameter of the piston 2 isless than the inner diameter of cylinder 1 so that there is a clearanceformed between the circumferential edge of the piston 2 and the innerwall of the cylinder 1.

Formed in the vertical peripheral edge surface of the piston 2 is anannular groove 12 into which is positioned a sealing ring 13. Thissealing ring 13 has a diameter less than the area between the side wallsof the groove 12 so that it has a limited vertical movement therein.Also formed in the piston 2 are a plurality of passages 11 which extendbetween the annular groove 12 and intake ports 11' formed in the upperend of the piston 2.

Each of the pumping chambers 9 and 10 are provided with suction openings14 and 17 provided with valve arrangements 15 and 18, respectively. Asshown in FIG. 1 the lower pumping chamber 9 has provided in the end wall5 of the cylinder 1 a number of apertures 14 which serve as suctionopenings disposed about the piston rod 6. Circumferentially extendingabout the piston rod 6 is an inner annular wall 16' which supports aretaining member 16 in a spaced relation to the end wall 5 of thecylinder 1. Between the end wall 5 and the retainer member 16 anddefined by the annular wall 16 is a chamber 15 which houses a sealingring 15 frictionally mounted on the piston rod 6.

The top wall of the cylinder 1 is provided with a plurality of suctionholes 17 which have open communication with the upper pumping chamber10. The top Wall of cylinder 1 also provides a ring 18' extendingcircumferentially about a mounting stud 17 upon which is fixedly secureda flexible diaphragm 18 that normally closes the suction holes 17.

In the position shown in FIG. 1 the cylinder 1 has commenced itsvertical movement caused by moving the cylinder 1 away from the supportplate 7. Because of the friction between the piston rod 6 and thesealing ring 15, such ring 15 will have been moved downwardly throughthe chamber 15 against the bottom wall 5 so as to seal the apertures 14formed therein to prevent the acting medium within the pumping chamber 9from escaping therethrough. It should also be noted that the pressurecreated within the reducing pumping chamber 9 will assist in pressingthe ring 15 downward upon the wall 5 to seal the openings 14 formedtherein.

By the upward movement of the cylinder 1 the sealing ring 13 whichexerts frictional pressure against the inner wall of the cylinder 1 willbe caused to move into abutment with the upper inner wall surface of thegroove 12 so as to effect a seal between that portion of the annulargroove 12 and the inner wall of the cylinder 1. This movement of thesealing ring 13 within the annular groove 12 provides a gap between thesealing ring 13 and the lower wall surface of the groove 12 and openscommunication between the pumping chamber 9 and the passages 11 formedin the piston 2. Thus as the cylinder 1 is caused to move vertically asseen in FIG. 1 the medium in the pumping chamber 9 is forced through thepassages 11 and into the hollow piston rod 6 and into the hose 8 forexhaust through the nozzle 19.

During the upward movement of cylinder 1 relative to the piston 2 thevacuum created in the enlarging pumping chamber 10 will cause theflexible diaphragm 18 to flex inwardly and expose the openings 17 formedin the top wall 4 to admit air therethrough into the chamber 10.

Upon downward movement of the cylinder 1 the sealing ring 13 will becaused to move in abutment with the lower wall surface of the groove 12and thus expose the passages 11 to the pumping chamber 10 forcing themedium therein out of the pump. The back pressure created by thismovement of the cylinder 1 will effectuate the sealing of the flexiblediaphragm 18 on the openings 17 to close the same to prevent theescapement of the medium therethrough. The downward movement of thecylinder 1 will cause the sealing ring 15 to move into abutment with theretainer 16 opening communication with the openings 14 formed in thebottom wall 5 of the cylinder 1 to admit air into the enlarging pumpingchamber 9.

FIG. 2 illustrates a modified embodiment of the valve arrangement in thepiston 2 which alternately connects the pumping chambers 9 and 10 withthe hollow piston rod 6. Passing from each of the pumping chambers 9 and10 to the interior of the piston rod 6 are passages 20 and 21,respectively. The mouths of the passages 20 and 21 are suitably situatedopposite each other in the side wall of the piston rod 6. Located withinthe upper end of the piston rod 6 is a bell-shaped valve member 22 whichlies against the inner wall of piston rod 6 and covers the mouths of thepassages 20 and 21.

When using the pump as shown in FIG. 2 the medium pressure in one or theother passage 20 and 21 (depending on relative direction of movementbetween cylinder 1 and piston 2) will increase and deflect the wall ofthe valve member 22 away from one of the passages allowing the medium toflow into the hollow piston 6. Thus upward movement of cylinder 1 asviewed in FIG. 2 would effect opening passage 20 while downward movementof the cylinder 1 would open passage 21.

In FIG. 3 the piston 2 as shown is provided with a sealing ring 23 whichis substantially U-shaped in cross-section with the open portion thereofturned in toward the base of the annular groove 12. The U-shaped sealingring 23 fits within the groove 12 without any appreciable pressureagainst the upper and lower walls thereof, and the edges of the sealingring 23 are free to be deflected away by the pressure prevailing ineither one of the pumping chambers 9 and 10 to permit the medium to passabout the sealing ring 23 and flow into the passages 11 and out of thepiston rod 6.

The above description has been made with respect to an air pump, but itshould be understood that the invention so described can be applied to apump intended for other gases as well as for liquids without departingfrom the scope of the present invention.

While I have illustrated and described the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modification without departing from the spirit of theinvention. I, therefore, do not wish to be limitedto the precise detailsof construction set forth, but desire to avail myself of such variationsand modifications as come within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire toprotect by Letters Patent is:

1. A double-acting piston pump for a gas or liquid medium including ahollow cylinder and a piston therein dividing the cylinder into twopumping chambers with the cylinder and piston movable relative to eachother to change the volume of the pumping chambers wherein theimprovement comprises:

(a) a hollow piston rod closed at one end by the piston;

(b) passages formed through said piston providing open communicationwith said hollow piston rod and the pumping chambers;

(c) valve means carried by said piston for selectively sealing one oithe pumping chambers against open communication with the hollow pistonrod while simultaneously permitting open communication with the otherpumping chamber; and

(d) said valve means comprises a flexible bell-shaped gasket whichnormally closes the passages formed in said piston with a portion of thebell-shaped gasket being deflected away from one of the passages by theincreasing exhaust pressure of the medium in one of the pumping chambersas said cylinder is moved relative to said piston.

2. The pump of claim 1 further defined by having pressure responsivevalve members at opposite ends of the hollow cylinder for admitting themedium into one or the other pumping chambers in response to thedirectional movement of the cylinder with respect to the piston.

References Cited UNITED STATES PATENTS 90,940 6/1869 Forrester 103l58309,662 12/1884 Stoufler 103-188 711,654 10/1902 Byars 103-190 1,278,2649/1918 Weinman 103192 1,830,258 11/1931 Bohnenblust 103192 FOREIGNPATENTS 483,009 7/ 1951 Italy. 742,293 11/1943 Gennany.

HENRY F. RADUAZO, Primary Examiner US. Cl. X.R.

